JP5133556B2 - Microbubble generator - Google Patents

Description

  The present invention relates to an apparatus for generating fine bubbles in a liquid.

In sewage treatment and aquaculture, in order to activate bacteria for water treatment or to cultivate and activate aquatic organisms, it is effective to diffuse oxygen (aeration) by diffusing bubbles in water Are known. Also, in the industrial field and the like, it is widely known that it is effective to diffuse bubbles in a liquid in order to promote a gas-liquid reaction.
For these purposes, the bubble size should be as fine as possible so that the buoyancy of the bubbles is reduced and stays longer in the liquid, and the surface area in contact with the liquid is increased to increase the reaction efficiency. desirable.

As a method for diffusing bubbles in water, conventionally, for example, a method in which compressed air from a compressor is discharged from pores such as a diffuser pipe in water, or a method in which mixing and stirring is performed by rotating an impeller in water is the most common. It was the target.
However, in these methods, not only the cost of the equipment is increased and the maintenance is troublesome, but also the degree of refinement is insufficient and the generated bubbles are relatively small if the mixture is simply discharged from the pores or mixed and stirred in water. There was a disadvantage that it remained large and generation of fine bubbles was difficult.

Therefore, various proposals have been made in recent years for the purpose of generating fine bubbles.
(1) A liquid and a gas are mixed and pressurized to dissolve the gas in the liquid, and then the gas-liquid mixture is decompressed to generate fine bubbles. (For example, see Patent Document 1)
(2) Fine bubbles are generated by mixing gas while rapidly ejecting liquid from the nozzle. (For example, see Patent Document 2)
(3) A micro-bubble is generated by generating a swirling flow of liquid in the container and stirring and shearing the mixed gas. (For example, see Patent Document 3)
(4) A stationary mixer is installed, and the gas-liquid mixture collides with the baffle plate and the collision protrusion and is stirred to generate fine bubbles. (For example, see Patent Document 4)

JP-A-11-207162 JP 2001-58142 A Japanese Patent Laid-Open No. 10-230150 JP 2002-85949 A

However, these conventional techniques (1) to (4) have the following problems.
In (1), the equipment itself such as a pressurized tank becomes large and expensive, and it takes time to pressurize and is uneconomical.
In (2), since liquid and gas are only ejected from the nozzle, fine adjustment is required, and it is difficult to generate a large amount of fine bubbles in a short time.
(3) requires fine adjustment for stable generation of fine bubbles, and unattended long-time operation is difficult. In addition, when a cyclonic swivel mechanism with a spiral inflow path is used and the swirl force depends on the kinetic energy of the liquid itself, sufficient swivel force cannot be obtained due to lack of energy. It is difficult to generate a large amount of fine bubbles in a short time.
Since (4) relies on simple collisions, the refinement effect is not sufficient. In addition, the energy loss due to the resistance of the static mixer is large, and power for feeding the gas-liquid mixture is required.

In any of (1) to (4), the role of mixing gas in the liquid to generate a gas-liquid mixture or pushing the liquid or gas-liquid mixture into the bubble generating device is separately Since it is assigned to the installed pressure pump, it requires double equipment such as a bubble generator and a pump, and there is a problem that the cost is high, and the performance of the bubble generator is highly dependent on the performance of the pump There is also a problem that it must be done.
Furthermore, when it applies to the process which handles foodstuffs or high purity liquid, there exists a problem that washing | cleaning is not easy. Normally, the equipment used for this purpose is “sanitary specification”, and not only the wetted surface is finished smooth, but also cleaning in place (internal cleaning without disassembly), disassembly cleaning and reassembly can be performed easily. Although it is essential to have a structure, the conventional apparatus has a complicated structure or a bottleneck in the flow path, so that the disassembling work is complicated and the wetted part is not affected by stationary cleaning. It is also difficult to clean. Also, clogging is likely to occur.
As described above, each of the above conventional techniques has a problem in that there are limitations in both cost and performance.

  Accordingly, the present invention can generate a large amount of fine bubbles in a liquid in a short time stably and efficiently with a simple structure, and can be manufactured inexpensively regardless of whether the apparatus is small or large. The objective is to obtain a high-performance, easy-to-handle microbubble generator that can be easily cleaned in place and disassembled to satisfy sanitary specifications, and can be applied to various applications and liquid qualities.

In order to achieve the above object, an apparatus according to the present invention provides:
A casing having a first opening and a second opening through which fluid enters and exits is provided with an impeller that rotates to impart swirling energy to the fluid, and the casing is formed to surround an outer edge of the impeller The impeller housing portion and a reduced diameter portion that gradually reduces the diameter from the impeller housing portion to speed up the swirling of the fluid. A first opening is provided near the tip of the reduced diameter portion, and the blade A second opening is provided in the vicinity of the vehicle accommodating portion, and the flow direction of the fluid is set to either the direction from the first opening toward the second opening or the direction from the second opening toward the first opening. In this case, the main feature is that the fluid is forcibly given a turning force by the rotation of the impeller .

In the present invention, the impeller may be integrally formed with a stirring blade portion that stirs fluid and a discharge blade portion that applies discharge pressure to the fluid .
Further, the casing may form a single chamber space that is integral and has no partition wall or narrow portion .
Further, a guide for twisting the fluid in a predetermined direction, an orifice for constricting the fluid, and a tail bottom portion of the tornado-like cavity generated by the rotation of the impeller are received in the fluid flow path near the first opening. For example, it may be provided with at least one of a hollow receiver for the purpose and a concavo-convex part or a concavo-convex member for stirring the fluid .
In addition, the impeller is formed in a shape that generates a turbulent flow due to the rotation direction of the fluid particles that collide during rotation is closer to the rotation center than the rotation tangential direction at least on a part of the impeller. it may be.
Moreover, you may provide the uneven | corrugated | grooved part or uneven | corrugated member for stirring the fluid in at least one of the inner wall part of the said casing and the said impeller .

Further, a vent may be provided in the vicinity of the rotation center line of the impeller, and the vent may be communicated with any one of a vacuum device, a gas injection device, and an air release port.
Moreover, you may provide the pump action which pumps a fluid toward the 2nd opening from the said 1st opening, or toward the 1st opening from the 2nd opening.
Moreover, you may provide the self-priming pump action which sucks up the fluid.

With this configuration, in the apparatus of the present invention, the built-in impeller gives powerful swirling energy to the fluid, and the reduced diameter portion of the casing speeds up the swirling to produce a sudden vortex / turbulent flow. Can be generated in a short time in a large amount, stably and efficiently. Further, the generation of further fine bubbles is promoted by stirring, shearing, and cavitation due to the vortex or turbulent flow generated by the shape of the impeller.
This device performs both gas-liquid mixing and bubble miniaturization to generate fine bubbles, but also can apply a discharge pressure to the fluid by a pump action, or can self-suck. In addition, the structure is simple, the device can be manufactured at a low cost regardless of whether it is small or large, and it can be easily washed in place and disassembled to satisfy the sanitary specifications, and can be applied to various applications and liquid qualities.

  In the following, the same reference numerals are given to common parts throughout the drawings, and details of each embodiment of the present invention will be described.

FIG. 1 shows a first embodiment of the present invention, FIG. 2 shows an II cross section in FIG. 1, and FIG. 3 shows an II-II cross section in FIG.
A casing having two openings serving as an inlet and an outlet for fluid can be divided into 1a and 1b, and is formed so as to constitute one substantially cylindrical chamber when they are joined together. 1b is provided with an impeller 2 having an appropriate number of blades.
The impeller 2 is attached to the rotary shaft 3 by a screw type or an impeller nut as illustrated in the figure. The rotary shaft 3 is supported by the bearing portion 5 and hermetically penetrates the casing 1b by the shaft seal portion 4, and is rotated by a prime mover (not shown).
The impeller 2 is formed with an agitating blade portion 2m that performs an agitating action over the entire rotation peripheral portion. In particular, a portion in the vicinity of one axial end portion (the left end surface in FIG. 1) 2r is lifted. The diameter of the discharge blade 2d is increased to give a discharge force (discharge pressure) to the liquid.

The casing 1a includes an impeller accommodating portion 1x formed so as to surround the outer edge portion of the impeller 2, and a reduced diameter portion 1y formed so as to gradually decrease in diameter as the distance from the impeller accommodating portion 1x increases. The first opening a is provided in the vicinity of the tip of the reduced diameter portion 1y, while the second opening b is provided in a portion facing the discharge blade portion 2d in the vicinity of the impeller housing portion 1x. ing.
In the present embodiment, the first opening a is a fluid inlet, and the second opening b is a fluid outlet. On the first opening a (fluid inlet) side, an inlet valve 6 for adjusting the amount of pumped liquid flowing into the apparatus, and a gas for adjusting the amount of gas mixed with the flow of pumped liquid An injection valve 7 is provided, and an outlet valve 8 for adjusting the amount of outflow from the apparatus is provided on the second opening b (fluid outlet) side.
In the vicinity of the shaft seal portion 4 of the casing 1b through which the rotary shaft 3 passes, a cavity is formed and a cleaning liquid inlet c is provided so that the inside of the apparatus can be cleaned without being disassembled.

When the apparatus of this embodiment is operated, the pumped liquid is guided from the opening a to the opening b by the pumping action of the discharge blade portion 2d, and the gas is sucked in via the gas injection valve 7 (or the air supply). The fluid (gas-liquid mixture) composed of the pumped liquid and the gas is generated.
This fluid is forcibly swirled by the impeller 2 and continues to be given strong swirling energy from the impeller 2, so that the swirling energy does not become deficient, and a much stronger swirling force compared to a simple cyclone type or the like. Will occur.
At this time, if the outlet valve 8 on the opening b side is throttled by a predetermined amount, a part of the fluid stays in the casing for a predetermined time and continues to turn, but the turning speed is within the reduced diameter portion 1y. As the turning radius decreases, the speed becomes higher, and a very high speed turning flow is formed in the vicinity of the opening a at the tip. Therefore, if a fluid is continuously introduced from the opening a, the fluid is exposed to a high-speed swirling flow at the moment when it flows into the reduced diameter portion 1y, and a strong vortex flow is generated by a sudden change from a non-turning state to a high-speed swirling state. It becomes a turbulent flow, and bubbles in this fluid are agitated / sheared and refined.

  In addition, the fluid is subjected to stirring / shearing due to contact with the impeller 2 and stirring / shearing due to viscous friction with the inner wall of the casing. Furthermore, vortex / turbulence is mainly generated in the vicinity of the reduced diameter portion 1y of the casing. Cavitation is also generated, thereby promoting further bubble destruction and generation of fine bubbles. Together, these make the bubble refinement extremely powerful.

This device is also equipped with a structure that can be easily cleaned in place and disassembled to satisfy sanitary specifications, and can be applied to various applications and liquid qualities.
When this apparatus is cleaned in place, the casing 1a; 1b forms only one chamber space that is integral and has no partition wall or narrow portion, so that it can be cleaned easily and thoroughly. it can. Specifically, the inside of the casing 1a side may be cleaned by injecting a cleaning liquid from the opening a while operating the apparatus and discharging it from the opening b; the drain port d. The cleaning liquid may be injected from the cleaning liquid injection port c and discharged from the opening b; the drain port d. In this way, the wetted part can be washed without shadow. In addition, it is convenient in terms of operation if a cleaning liquid injection valve 13; a drain valve 14 is attached to the cleaning liquid injection port c and the drain port d and is closed except during cleaning.

  Also, when disassembling and cleaning this apparatus, the casing can be easily divided into 1a and 1b without being caught, and the impeller 2 is exposed at the time of division, so the wetted part on the casing 1a side should be washed without shadows. In addition, since the integrally formed impeller 2 can be easily pulled out from the rotating shaft 3 without being obstructed by other members, it is easy to clean the liquid contact part on the casing 1b side. It is easy to reassemble. As for the installation method of this casing, the 1b side may be fixed and the 1a side may be removable, and conversely the 1a side may be fixed and the 1b side including the rotating body part may be removable (so-called back pull-out method). Also good.

  In addition to general uses such as efficiently dissolving gases such as air, oxygen, and ozone in liquids such as water, food, oil, and chemicals by miniaturizing bubbles, this device can be used for gases. For a wide range of applications, such as the production of foamed creams.

4 shows a second embodiment, FIG. 5 shows a cross section taken along line II in FIG. 4, and FIG. 6 shows a cross section taken along line II-II in FIG.
In this embodiment, the guide 15 for twisting the fluid in a predetermined direction is first provided in the fluid flow path near the first opening a in the structure of the casing reduced diameter portion 1y. In particular, if the fluid is twisted in the direction opposite to the rotation direction of the impeller 2 as shown in the drawing, there is an effect that the degree of stirring / shearing with respect to the fluid can be further increased.
As for the shape of the reduced diameter portion 1y, it is exemplified that a swelled shape may be appropriately designed instead of the simple cone shape as in the first embodiment. By the action of the reduced diameter portion 1y, the fluid to which the turning force is applied from the impeller 2 becomes a high-speed swirling flow, and the agitation is instantaneously performed by a sudden change from the non-turning state before the inflow from the opening a to the high-speed turning state. The generation of fine bubbles by shearing is the same as in the first embodiment.

  Further, the impeller 2 has a blade shape that generates a turbulent flow by rotation in order to further increase the stirring / shearing ability of the apparatus. That is, the impeller 2 of the present embodiment is intentionally lowered in efficiency, increased in resistance, and turbulent, contrary to a streamlined centrifugal blade with low resistance and loss in consideration of pump efficiency like a general pump impeller. As a specific example, the reflection direction A of the fluid particles colliding with the blades is closer to the center of rotation than the rotation tangential direction B. For this reason, the centrifugal force C that tends to flow toward the outside of the rotation acts on the fluid that is given kinetic energy from the impeller 2, while the acting force near the center of rotation that tends to flow toward the inside of the rotation is also present. work. Also, due to the specific gravity of the fluid itself, a heavy liquid tends to go outward while a light gas tends to go inside. These opposing movements create a strong vortex and turbulence, which further stirs and shears the bubbles.

The impeller 2 preferably includes a concavo-convex portion or a concavo-convex member for stirring the fluid. In the present embodiment, as an example, the impeller 2 includes a porous concavo-convex portion 2 u provided with an appropriate number of holes. Moreover, it is preferable that the inner wall portion of the casing 1a is also provided with an uneven portion or an uneven member for stirring the fluid. In the present embodiment, as an example, a bowl-shaped uneven member 1u is disposed along the inner wall. It is. And the clearance gap between the impeller 2 and the uneven | corrugated member 1u is set small.
Therefore, in addition to the stirring / shearing effect by the concavo-convex portion 2u and the concavo-convex member 1u, the shear between the two members due to the small gap between the impeller 2 and the concavo-convex member 1u also works strongly, and further, due to eddy current / turbulence Combined with the occurrence of cavitation, the bubble refinement is extremely powerful.

  A vent e is provided near the center of the impeller 2, that is, in the vicinity of the rotation center line of the impeller 2 (in this embodiment, the vent e is also used as the cleaning liquid inlet c. ), The vent e is communicated with any one of the vacuum device 9, the gas injection device 10, and the air opening g through the vent passage f. In the present embodiment, all of them are shown for simplicity of explanation, but it goes without saying that any one may be selected according to the specifications of the site.

  If there is a large bubble that cannot be miniaturized, it will accumulate near the center of the impeller 2 by the rotation of the impeller 2 to form a tornado-shaped cavity. In order to discharge the apparatus out of the system, the vent e may be connected to the vacuum apparatus 9. In addition, communication with the vacuum device 9 is also effective when the self-priming pump action is desired. On the other hand, if it is desired to introduce gas instead of introducing gas at the stage before the opening a, the vent e may be communicated with the gas injection device 10. Depending on the operating conditions, gas may be discharged / introduced only by connecting the vent e to the air opening g.

Reference numeral 11 in the figure denotes protection means for preventing the passage of the pumped liquid and allowing only the gas to pass through when the pumped liquid is mixed in the gas passing through the air passage f. It is possible to prevent the pumped liquid from entering 10 and to ensure the safety of the apparatus. For example, the protection means 11 includes an inlet and an outlet at the top of the container, and a liquid storage tank type formed so that the pumped liquid that has entered through the air passage f stays at the bottom of the container and only gas components can pass through, A well-known type may be used, such as a float valve type that forcibly closes the air passage f when the liquid level in the air passage f rises.
The vacuum device 9 may be a liquid ring vacuum pump, other types of vacuum pumps or negative pressure generators, and the gas injection device 10 may be a compressor or other types of pressure generators.

  The device of the present embodiment also exhibits a pumping action by the device itself. However, when it is desired to provide not only such a pumping action but also a self-priming pumping action for sucking up a fluid, the vent e In addition to the method of contacting the vacuum device 9 with respect to the structure of the discharge blade portion of the impeller 2 and the casing portion (vortex chamber) corresponding thereto, the technology of the self-priming pump such as JP-B-50-21682 is used. There is also a method to apply.

In this embodiment, the impeller 2 itself is formed so as to easily generate cavitation due to turbulent flow, but in order to further promote the occurrence, Cavitation generating means may be additionally installed (not shown). By generating cavitation, it is possible to increase the generation efficiency of fine bubbles by promoting the precipitation, bubbling and refinement of dissolved gas in the pumped liquid, and by using the impact at the time of collapse of the cavitation, It is expected to have effects such as removal of stuck foreign substances, sterilization, deodorization, atomization of contained particles, compositional destruction of mixed impurities, and water cluster decomposition. As a method for generating cavitation, there are an ultrasonic oscillation type, a rotary propeller type, and the like, which may be appropriately selected.
Other configurations and operations of the present embodiment are the same as those of the first embodiment.

7 shows a third embodiment, FIG. 8 shows a cross section taken along the line II in FIG. 7, and FIG. 9 shows a cross section taken along the line II-II in FIG.
In the present embodiment, for the structure of the casing reduced diameter portion 1y, an orifice 16 for constricting the fluid is provided in the fluid flow path near the first opening a. This has the effect of promoting the generation of turbulent flow when passing through the orifice and further enhancing the degree of agitation / shearing of the fluid.
The opening a is provided with a cavity receiver 17 for receiving the tail of the tornado-shaped cavity when a tornado-shaped cavity is generated by the rotation of the impeller 2, and the pumped liquid flows in from the side. The example was illustrated. Since the pumped liquid is forcibly swirled by the impeller 2, the flow path shape and the inflow angle of the opening a may be appropriately selected. In this figure, the flow path of the opening a is illustrated as being formed in a shape that is wound along the rotational direction of the impeller 2, but conversely formed in a shape that is wound in the opposite direction of rotation. Doing so may help promote turbulence.
As for the shape of the reduced diameter portion 1y, it has been exemplified that a trumpet shape may be appropriately designed instead of a simple cone shape.

  As for the impeller 2, as an example of a blade shape that generates turbulent flow, the stirring blade portion 2 m is similar to the second embodiment in that the reflection direction of the fluid particles colliding with the blade is closer to the rotation center than the rotation tangential direction. On the other hand, in the same way as a normal pump impeller, the discharge blade portion 2d is formed so that the reflection direction of the fluid particles colliding with the blade is more outward than the rotational tangential direction. Dare to create a movement in the direction to do.

  As an example of an uneven portion (an uneven member) for stirring the fluid, the stirring blade portion 2m is provided with a comb-like uneven portion 2u, and an inner wall portion of the casing 1a is provided with a bowl-shaped uneven member 1u along the inner wall. In order to enhance the shearing effect, the gap between the impeller 2 and the concavo-convex member 1u in the impeller accommodating portion 1x is set small.

  On the other hand, one axial end portion (left end surface in FIG. 7) 2r of the impeller 2 is formed to slide while keeping a predetermined gap as small as possible with respect to the inner wall of the casing 1b. Further, in the vicinity of the central portion of the casing 1b facing the sliding impeller end 2r, that is, in the vicinity of the rotation center line of the impeller 2, the cavity gas generated by the rotation of the impeller 2 is discharged or conversely gas Or the like, as in the second embodiment, the vent e communicates with any one of the vacuum device 9, the gas injection device 10, and the air release port g through the vent passage f. Has been.

  In this embodiment, as an alternative to the protection means 11 in the second embodiment, the impeller end 2r is configured to slide while maintaining a predetermined gap as small as possible with respect to the inner wall of the casing 1b. With this configuration, the passage of the gas is allowed and the passage of the pumped liquid is prevented, thereby preventing the pumped liquid from entering the vacuum device 9 and the gas injection device 10. That is, even if the pumped liquid enters the vent hole e, the liquid component having a mass larger than that of the gas is swung away by the centrifugal force of the impeller end 2r, and the impeller end 2r slides with the casing 1b. Since the gap is small, the liquid component cannot enter from here, and therefore the liquid is not pumped to the vent e during this operation, so the vacuum device 9 and the gas injection device 10 are safe.

And just in case, the thing which attached the baffle member 2p which prevents the pumping liquid of the rotation shaft 3 vicinity to penetrate | invade into the vent hole e straightly was illustrated near the impeller end 2r. The baffle member 2p can have an appropriate shape such as a plate shape or a lump shape. However, in this embodiment, a plate-like member is used, and an appropriate number of holes and slits communicating the front side and the back side. The thing made into the shape of a side plate (shroud) with an attachment was illustrated. As a result, when the liquid component tries to invade straightly toward the vent e, it is shaken off by the baffle member 2p and is prevented from passing, and the gas can pass only through the hole or slit. Can be fulfilled.
Other configurations and operations of the present embodiment are the same as those of the second embodiment.

FIG. 10 shows a fourth embodiment, FIG. 11 shows an II cross section in FIG. 10, and FIG. 12 shows an II-II cross section in FIG.
In this embodiment, first, an uneven portion 1u for stirring the fluid is provided on the inner wall of the casing reduced diameter portion 1y. This has the effect of promoting the generation of turbulent flow and further enhancing the degree of stirring and shearing of the fluid. As the uneven portion, an appropriate shape may be selected in addition to the illustrated dimple shape, or an uneven member may be attached.

As for the impeller 2, as an example of a blade shape that generates turbulent flow, the discharge blade portion 2 d is formed so that the reflection direction of the fluid particles colliding with the blade is closer to the rotation center than the rotation tangential direction. The part 2m has a simple radiation blade shape. The impeller 2 includes a porous uneven portion 2u for stirring the fluid.
Further, the discharge blade portion 2d is provided with a side plate (shroud) that is easy to obtain discharge pressure. Even in the case with the side plate, an appropriate shape and number of notches are formed in the peripheral portion of the side plate, An example is considered in which the cleaning liquid injected from the cleaning liquid injection port c at the time of stationary cleaning can flow smoothly toward the drain port d without staying by communicating.

The shape of the cavity near the shaft seal portion 4 where the cleaning liquid inlet c is opened may be any shape as long as the cleaning liquid is less likely to stay, but in the present embodiment, as an example, it has a cone shape. Things are illustrated. If the cleaning liquid inlet c is provided near the reduced diameter portion of the cavity, the injected cleaning liquid is discharged from the reduced diameter portion to the drain port d through the enlarged diameter portion. Further, if the cleaning liquid inlet c is formed in a flow channel shape that is tangentially inserted into the cavity, the injected cleaning liquid is thoroughly discharged so as to lick the inside of the cavity, and thus the cleaning effect is improved. Further improvement can be achieved.
Other configurations and operations of the present embodiment are the same as those of the first embodiment.

FIG. 13 shows a fifth embodiment, FIG. 14 shows an II cross section in FIG. 13, and FIG. 15 shows an II-II cross section in FIG.
In the present embodiment, with respect to the impeller 2, the discharge blade portion is removed and only the stirring blade portion 2 m is provided, and the pump action is performed by a separate pump 12. In this figure, the pump 12 is provided on the second opening b side, but may be provided on the first opening a side.
In the figure, the flow direction is directed from the opening b to the opening a, and accordingly, the inlet valve 6 and the gas injection valve 7 are on the opening b side, and the outlet valve 8 is on the opening a side. Is provided. In this case, the liquid feeding direction of the pump 12 may be reversed so that the flow direction is from the opening a to the opening b. In this case, of course, the inlet valve 6 and the gas injection valve 7 are on the side of the opening a. The outlet valve 8 is provided on the opening b side.

For the impeller 2, as an example of a blade shape that generates turbulent flow, the reflection direction of the fluid particles colliding with the blade is closer to the rotation center than the rotation tangential direction, and the reflection direction is more outward than the rotation tangential direction. Exemplified are blades that are alternately arranged and coexist.
Ventilation for discharging the cavity gas generated by the rotation of the impeller 2 or introducing the gas in the vicinity of the central portion of the impeller 2, that is, in the vicinity of the rotation center line of the impeller 2. As in the second to third embodiments, the vent e is communicated with any one of a vacuum device, a gas injection device, and an air release port (not shown) by the vent passage f. ing.
In addition, as an example of the concavo-convex portion (concave member) for stirring the fluid, a truncated concavo-convex member 18 is provided in the fluid flow path near the opening a of the casing, or the porous concavo-convex portion is provided on the impeller 2. It was also shown that 2u may be provided.

The bubble miniaturization process is the same as in the first embodiment. That is, the fluid composed of the pumped liquid and the bubbles is forcedly and continuously given a turning force by the rotation of the impeller 2 and is turned into a high-speed swirling flow by the action of the casing reduced diameter portion 1y. For this reason, when the fluid flows continuously from the opening a, it is agitated and sheared instantaneously by a sudden change from the no-turning state to the high-speed turning state, and fine bubbles are generated. On the contrary, as shown in the figure, when flowing in from the opening b and flowing out from the opening a, the fine bubbles are stirred and sheared by a sudden change from the high-speed turning state to the non-turning state (or turning suppression state). Is generated.
In addition, stirring / shearing due to vortex / turbulence generated by the shape of the impeller 2, stirring / shearing due to the concavo-convex member 18 near the opening a or the concavo-convex portion 2 u of the impeller 2, and further eddy current / turbulence Combined with the occurrence of cavitation due to flow, the refinement of bubbles is extremely powerful.

In addition, about the location where the fluid flows in and out of the casing, that is, the opening a and the opening b, the flow channel shape and the inflow angle may be appropriately selected. It is illustrated that it may be a simple opening without being formed into a shape.
Other configurations and operations of the present embodiment are the same as those of the first embodiment.

FIG. 16 shows a sixth embodiment, FIG. 17 shows an II cross section in FIG. 16, and FIG. 18 shows an II-II cross section in FIG.
The present embodiment eliminates the need for the pump 12 of the fifth embodiment by generating thrust in the rotational axis direction by adopting an appropriate number and shape of axial flow blades as the discharge blade portion 2d for the impeller 2. Further, the configuration around the vent e is also omitted, and the entire apparatus is collected more compactly than the fifth embodiment.
In the figure, the flow direction is directed from the opening b to the opening a, and accordingly, the inlet valve 6 and the gas injection valve 7 are on the opening b side, and the outlet valve 8 is on the opening a side. Is provided. This may be achieved by reversing the rotation of the rotary shaft 3 so that the flow direction is from the opening a to the opening b. In this case, of course, the inlet valve 6 and the gas injection valve 7 are provided on the side of the opening a. The valve 8 is provided on the opening b side.

About the stirring blade part 2m of the impeller 2, what was made into the shape of the simple radiation blade was illustrated as an example of the blade shape which generates a turbulent flow.
In addition, as an example of the uneven part (uneven member) for stirring the fluid, a pile-like uneven member 18 is provided in the fluid flow path in the vicinity of the opening a of the casing, or the impeller 2 has a porous shape or a comb-like shape. It was also shown that the uneven portion 2u may be provided.
Other configurations and operations of the present embodiment are the same as those of the fifth embodiment.

Next, technical matters common to the embodiments will be described.
In each embodiment, an example is shown in which a pumped liquid flowing in via the inlet valve 6 and a gas flowing in via the gas injection valve 7 are mixed to produce a gas-liquid mixture. Needless to say, the gas-liquid mixture produced in advance may be supplied to the apparatus. In this case, of course, the gas injection valve 7 is unnecessary.
The shape of the casing reduced diameter portion 1y may be appropriately designed such as a beverage bottle shape in addition to the cone shape and the trumpet shape exemplified in each embodiment.
About the division | segmentation location of a casing, you may select an appropriate location not only in the location shown in each figure but on design. The number of divisions is not limited to two, and may be three or more if there is no problem in decomposition and cleaning.

About the direction of the rotating shaft 3, you may select a horizontal axis type, a vertical axis type, and a diagonal axis type suitably. Of course, the opening a, the opening b, the cleaning liquid inlet c, the drain port d and the like are arranged at appropriate positions so that the cleaning liquid does not stay therewith.
The shaft sealing portion 4 and the bearing portion 5 of the rotating shaft 3 are shown attached to the casing 1b side, but conversely, they may be attached to the casing 1a side. In this case, the rotating shaft 3 has an opening a portion. What is necessary is just to design so that it may penetrate.
Further, the prime mover for rotating the rotary shaft 3 may be appropriately selected according to use conditions. For example, if this device is integrated with an underwater motor and the rotation shaft of the motor is used as it is as the rotation shaft 3 of the device, it becomes compact and no need to take measures against waterproofing the motor during cleaning. It is also possible to install the apparatus by submerging it in a liquid together with a motor.

  As for the impeller 2, in the first to fourth embodiments, the discharge blade portion 2 d and the stirring blade portion 2 m are integrally formed, but the discharge blade portion 2 d and the stirring blade portion 2 m are separated. It may be formed. As the type of the ejection blade portion 2d, various known types such as a non-clog type, an open type, a semi-open type, and a closed type can be applied. Even when a side plate (shroud) is provided, the front and rear surfaces are appropriately connected. For example, a communication path or a notch may be provided. Further, the discharge blade portion 2d may be formed on an axial flow blade, a diagonal flow blade, a screw, a propeller, or the like as in the sixth embodiment. Furthermore, the pumping action of the discharge blade portion 2d may be substituted by interposing a pump at an appropriate location in the flow path as in the fifth embodiment. In this case, the pump type is centrifugal. Various known types such as a pump, a mixed flow pump, an axial flow pump, a vortex pump, a diaphragm pump, and a gear pump may be appropriately selected.

As for the shape of the uneven portion (uneven member) 2u; 1u on the inner wall of the impeller or casing, in each embodiment, a porous shape, a dimple shape, a comb-like notch, a hook-like protrusion, a truncated protrusion, and a pile-like protrusion However, the present invention is not limited to these, and a shape suitable for the properties of the applied fluid, such as a mesh cutout or a plate-like protrusion, may be selected as appropriate. Further, in the case of specifications that do not require these uneven portions (uneven members), they may be omitted.
In order to further improve the performance of the present apparatus, the impeller 2 may be multistage, or a plurality of the apparatus may be connected and connected in series or in parallel. Various known vacuum devices and gas injection devices can be applied, and the number is not limited to one, and any vacuum device or gas injection device may be added.

In the present invention, the rotation of the impeller 2 and the shape of the casing diameter-reduced portion 1y produce a powerful and high-speed turning force, and the stirring and shearing by the strong vortex / turbulence generated by the shape of the impeller 2 and the like. Bubbles are refined extremely powerfully, but at the same time, the vortex and turbulence also generate cavitation, thereby promoting the generation of further fine bubbles. Further, by connecting the vent e to the vacuum device, the excess gas can be discharged appropriately.
Therefore, an operation method focusing on the generation of cavitation due to the vortex and turbulence and the exhaust by the vacuum device (for example, the gas injection path such as the gas injection valve 7 is completely closed, and the inlet valve 6 is kept in a squeezed state. Etc.), it is possible to deposit dissolved gas in the pumped liquid to form bubbles, and to collect and discharge the bubbles by centrifugation. This suggests that the microbubble generator of the present invention can be used for the purpose of “degassing and defoaming” by changing the operation method in addition to the purpose of “generation of microbubbles”. doing.

  In addition, within the scope of the present invention, various design changes can be made, such as changing the number, arrangement, and combination of the constituent elements and adding conventional means, and the material of the material can be selected as appropriate. The present invention is not limited to the embodiments described above.

The present invention provides a high-performance and easy-to-handle microbubble generator that can generate a large amount of microbubbles in a liquid in a short time in a short time with a simple structure.
This device performs both gas-liquid mixing and bubble miniaturization to generate fine bubbles, but also can apply a discharge pressure to the fluid by a pump action, or can self-suck. In addition, it has a structure that can be easily cleaned in place and disassembled to satisfy sanitary specifications, and can be applied to various applications and liquid qualities.
In addition to general applications such as efficient gas dissolution in liquids by miniaturization of bubbles, this device can be used for atomization without dissolving gas, for example, production of foam cream, It covers a wide field.
This device is simple in structure, has few failures, is durable, can operate completely automatically, does not require management, can be easily reduced in size and size, and can be implemented at low cost. It is very economical and its implementation effect is extremely large.

It is a longitudinal cross-sectional view (partial side view) which shows 1st Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG. It is a longitudinal cross-sectional view (partial side view) which shows 2nd Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG. It is a longitudinal cross-sectional view (partial side view) which shows 3rd Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG. It is a longitudinal cross-sectional view (partial side view) which shows 4th Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG. It is a longitudinal cross-sectional view (partial side view) which shows 5th Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG. It is a longitudinal cross-sectional view (partial side view) which shows 6th Example of this invention. It is II sectional drawing in FIG. It is II-II sectional drawing in FIG.

Explanation of symbols

1a; 1b ... casing 1u ... uneven part (uneven member)
1x ... impeller accommodating portion 1y ... reduced diameter portion 2 ... impeller 2r ... impeller end 2d ... discharge vane portion 2m ... stirring blade portion 2p ... baffle member 2u ... uneven portion (concave member)
DESCRIPTION OF SYMBOLS 3 ... Rotating shaft 4 ... Shaft seal part 5 ... Bearing part 6 ... Inlet valve 7 ... Gas injection valve 8 ... Outlet valve 9 ... Vacuum apparatus 10 ... Gas injection apparatus 11 ... Protection means 12 ... Pump 13 ... Cleaning liquid injection valve 14 ... Drain Valve 15 ... Guide 16 ... Orifice 17 ... Cavity receptacle 18 ... Uneven member a ... First opening b ... Second opening c ... Cleaning liquid inlet d ... Drain port e ... Vent port f ... Vent channel g ... Air release port A ... Fluid particle reflection direction B ... Rotational tangential direction C ... Centrifugal force direction

Claims (9)

A casing having a first opening and a second opening through which fluid enters and exits is provided with an impeller that rotates to impart swirling energy to the fluid, and the casing is formed to surround an outer edge of the impeller The impeller housing portion and a reduced diameter portion that gradually reduces the diameter from the impeller housing portion to speed up the swirling of the fluid, and a first opening is provided near the tip of the reduced diameter portion, and the blade A second opening is provided in the vicinity of the vehicle accommodating portion, and the flow direction of the fluid is set to either the direction from the first opening toward the second opening or the direction from the second opening toward the first opening. Even in the case where the fluid is generated, the fluid is forcibly given a turning force by the rotation of the impeller . 2. The fine bubble generating device according to claim 1, wherein the impeller is integrally formed with a stirring blade portion that stirs fluid and a discharge blade portion that applies discharge pressure to the fluid . The microbubble generator according to claim 1 or 2, wherein the casing forms a single chamber space that is integral and has no partition wall or narrow portion . In the fluid flow path in the vicinity of the first opening, a guide for twisting the fluid in a predetermined direction, an orifice for constricting the fluid, and a tail bottom portion of the tornado-like cavity generated by the rotation of the impeller The microbubble generator according to any one of claims 1 to 3, further comprising at least one of a hollow receiver and an uneven portion or an uneven member for stirring the fluid . The impeller is formed in a shape that generates a turbulent flow due to the reflection direction of the fluid particles that collide during rotation is closer to the rotation center than the rotation tangential direction at least on a part of the impeller. The fine bubble generating device according to any one of claims 1 to 4, wherein The microbubble according to any one of claims 1 to 5, wherein at least one of the inner wall portion of the casing and the impeller is provided with an uneven portion or an uneven member for stirring the fluid. Generator.   The vent is provided in the vicinity of the rotation center line of the impeller, and the vent is communicated with any one of a vacuum device, a gas injection device, and an air release port. 6. The fine bubble generator according to any one of 6 above.   8. The pump operation of pumping fluid from the first opening toward the second opening or from the second opening toward the first opening is provided. A device for generating fine bubbles according to crab.   The microbubble generator according to claim 8, further comprising a self-priming pump action for sucking up a fluid.

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